Broadcasting systems comprise broadcasting station apparatuses serving as transmission systems for transmitting program broadcasting signals from broadcasting stations, and receiving devices (e.g. television receivers or the like) serving as receiving systems for receiving the broadcasting signals transmitted by the broadcasting station apparatuses.
In a digital broadcasting system, a plurality of information are multiplexed on a broadcasting signal transmitted from a transmission system to a receiving system so that the function of the receiving system is diversified to meet viewers 'requirements.
For example, a service for presenting information relating to programs scheduled to be broadcast (hereinafter referred to as broadcasting scheduled programs) to viewers have been put to practical use. This service causes the information relating to the broadcasting scheduled programs to be multiplexed on a broadcasting signal as EPS (Electric Program Guide) data in a transmission system and be transmitted to a receiving system. In the receiving system, the EPG data is extracted from the fed broadcasting signal, so that the information relating to the broadcasting scheduled programs are presented to the viewer.
The information relating to the broadcasting scheduled programs can be displayed on a television screen by thus multiplexing the EPG data on the broadcasting signal. This makes it possible for the viewer to designate the desired broadcasting scheduled program on the basis of the displayed information relating to the broadcasting scheduled programs and reserve the designated program. Such a function that the viewer can reserve the desired broadcasting scheduled program is hereinafter referred to as a program reserving function.
Here, there is a character broadcasting receiving device comprising the program reserving function (see Patent Document 1, for example). In the EPG data used for the character broadcasting receiving device, a “program title”, a “broadcasting start time”, a “program end time”, a “channel”, and a “program identifier” are associated with each of the broadcasting scheduled programs.
The “program title” is the title of the associated broadcasting scheduled program, and the “broadcasting start time” is the time when the broadcasting scheduled program is scheduled to start. The “broadcasting end time” is the time when the broadcasting scheduled program is scheduled to end, and the “channel” is a channel on which the broadcasting scheduled program is broadcast. The “program identifier” is for identifying each of the broadcasting scheduled programs and a program that is being broadcast.
The EPG data is inputted to the character broadcasting receiving device, and the inputted EPG data is stored in a buffer memory as needed. In a case where the viewer reserves a desired broadcasting scheduled program (hereinafter referred to as a designated program), the EPG data relating to the designated program out of the EPG data stored in the buffer memory is stored in a reserved program memory. That is, the “program title”, the “broadcasting start time”, the “broadcasting end time”, the “channel”, and the “program identifier” that are associated with the designated program are stored in the reserved program memory.
Therefore, a microcomputer in the character broadcasting receiving device compares the “broadcasting start time” for the designated program stored in the reserved program memory with the current time measured by a timer circuit. The microcomputer tunes in to the “channel” for the designated program when the current time comes closer to the “broadcasting start time” for the designated program.
The microcomputer extracts the EPG data relating to the broadcasting scheduled program, which coincides with the “channel” for the designated program, out of the EPG data continuously stored in the buffer memory. Further, the microcomputer extracts the EPG data relating to the designated program out of the EPG data on the basis of the “program identifier” for the designated program.
Thereafter, the microcomputer compares the “broadcasting start time” and the “broadcasting end time” in the EPG data relating to the designated program extracted from the buffer memory with the “broadcasting start time” and the “broadcasting end time” for the designated program stored in the reserved program memory. Thus, it is determined whether or not there are changes in the “broadcasting start time” and the “broadcasting end time” for the designated program.
In a case where there are no changes, on the basis of the “broadcasting start time” and the “broadcasting end time” for the designated program stored in the reserved program memory, the designated program is recorded. On the other hand, in a case where there are changes, the “broadcasting start time” and the “broadcasting end time” for the designated program stored in the reserved program memory are changed on the basis of the EPG data relating to the designated program extracted from the buffer memory.
Thus, in the character broadcasting receiving device in Patent Document 1, when the “broadcasting start time” and the “broadcasting end time” for the designated program, which will be actually broadcast after being reserved, are changed, the “broadcasting start time” and the “broadcasting end time” for the designated program stored in the reserved program memory are changed on the basis of the “program identifier” in the EPG data inputted as needed.
In the current digital broadcasting system, pfEIT (present following Event Information Table) data is transmitted from a transmission system to a receiving system. The pfEIT data represents information relating to programs that are being currently broadcast and will be next broadcast. In the pfEIT data, the above-mentioned “program identifier”, “broadcasting start time”, and “broadcasting end time” are also associated with each of the programs that are being currently broadcast and will be next broadcast.
In a case where the pfEIT data is transmitted from the transmission system, the character broadcasting receiving device monitors the “program identifier” in the pfEIT data, and compares the EPG data relating to the designated program stored in the reserved program memory with the pfEIT data.
The character broadcasting receiving device extracts the EPG data relating to the designated program stored in the reserved program memory and the pfEIT data relating to the same program as the designated program on the basis of the “program identifier”. Therefore, the character broadcasting receiving device determines whether or not there are changes in the “broadcasting start time” and the “broadcasting end time” for the designated program, and changes the “broadcasting start time” and the “broadcasting end time” for the designated program stored in the reserved program memory when there are changes.
The character broadcasting receiving device thus makes it possible for the viewer to reliably record the designated program even in a case where the time when the designated program is broadcast is changed from the time point where the designated program is reserved to the actual time of broadcasting.
[Patent Document 1] JP 2000-50216 A